Main character — Opera Omnia

Main character — Duodecim

Accomplishments — Profile

Accomplishments — Pane

Synergy is going to be an important thing at a high level of play. That being said all the summons have potential because a lot of ex skills have potential. To me ex skills are best used to cover individual character weaknesses. For example as Kuja, I like revivify and HP Regen. Kuja wants to not die so both these help plus revivify helps compensate offensively since he has a hard time wall rushing at times so it allows me to chase easy. This makes Ramuh really good but only with other team mates using buff skills. As Kuja I like people who either like Ramuh for more offensive capabilities and survivability or Bahamut so I can get to Trance faster. That being said I know people like Ifrit and Shiva mostly but they have the potential of not helping much at all. My teammates? I like having a marksman and a vanguard that's good at applying pressure. Kuja tends to get targeted because of trance. Marksmaks require attention too and a good vanguard like Cloud can't be left alone either.
I would love to hear what other people like playing with and why.